Internship of Louis-Axel Edouard-Rambaut

This internship has been conducted (from the 23/04 to 26/09) during my Master 1 of Ecology. This work is a first report of the global emissions of N2O and NH3 estimated by the model. The localisation of the main emission, the evolution of the emissions and the response of the emissions with fertilizers have been described. The emissions estimated in ORCHIDEE have been compared with the one estimated by the inventory EDGAR. A work of hgarmonization have been conducted to allow a robust comparaison between the EDGAR sources and ORCHIDEE.

​Internship_report.pdf

I - EDGAR and ORCHIDEE

Differents simulations used in the comparaisons : S1B and S4

• S1B is obtnaied withe the following forcing : CLIM+CO2+LCLU+NDEP+NFER+MANN;
• S4 is obtained with the following forcing : CLIM+ CO2+LCLU

with CLIM:climate, CO2: atmospheric CO2, LCLU: land cover and land use change, NDEP: N deposition,NFER: N fertilizer use, and MANN: manure N use.
The simulations are located ​https://vesg.ipsl.upmc.fr/thredds/catalog/store/p529vui/OL2/PROD/NMIP-halfdeg/catalog.html :

To compare the emissions estimated in ORCHIDEE and in EDGAR, we only took agricultural soils emissions. For EDGAR we selected several Sources of emissions :

• Agricultural soils (4C + 4D) [AS]
• Indirect N2O emissions from agriculture (4D3) [I]

The total emissions of N2O we took in consideration is T = [AS] - [I] since the leaching flux are put out of the system in ORCHIDEE.

The emissions relatives to those sources are obtainable here in EDGAR (​http://edgar.jrc.ec.europa.eu/overview.php?v=432_GHG&SECURE=123)

The emissions are obtainable annualy, to get a single file for the period 1970-2012 we have to concatenate the files, for that i used NCO

" ncecat "name_of_file_1".nc "name_of_file_2".nc "name_of_file_n".nc "name_of_the_target_file".nc "

We compared these emissions estimated by EDGAR with the emissions of the PFTs 10, 11, 12 and 13.

Grid resolution :

• ORCHIDEE : 0.5°*0.5°
• EDGAR : 0.1°*0.1°

Period studied :

• ORCHIDEE : from 01/01/1861 to 31/12/2016, monthly emissions
• EDGAR : from 1970 to 2012, annual emissions

The R Script used in R are located at /home/users/ledouard with :

• annual review : Get the annual emissions
• maps : Get the repartition on a map of emission (via raster package)
• anthropîc mask : The script to get the mask used on ORCHIDEE to do the comparaison with EDGAR
• Regionnal mea, : Get the mean of emissions for differents regions for different sources and PFTs
• Regrid : The script to regrid the EDGAR grid to the same resolution as the grid of ORCHIDEE(the regrid can be performed with NCO and CDO)

The netCDF giles concerning EDGAR are located at /home/users/ledouard

the files concerning NH3 are not regrided (0.1°*0.10 resolution) whereas the N2O files are allready regrided (0.5°*0.5°)

II - N2O emissions

A - Emissions of N2O in ORCHIDEE

1 - Maps of emissions for the 2010-2015 period

Figure 1 : Emissions of N2O (in gN2O-N.m-2.years-1) estimated by ORCHIDEE for the 2010-2015 period for all the PFTs

2 - Evolution of the emissions for the 1861-2016 period

Figure 2 : Emissions of N2O (in gN2O-N.m-2.years-1) estimated by ORCHIDEE for the 1860-2015 period for the whole world

The regression is obtained with the ggplot2 package on r (type="loess") and is here only for a representative mean.

In black is represented the emissions for all the PFTs.

In blue is represented the emissions for the PFTs 12 and 13.

In green is represented the emissions for the PFTs 10, 11, 12 and 13.

In orange is represented the emissions for the PFTs 1 to 9

3 - Effects of the fertilizers on the emissions

Figure 3 : Global annual emissions of N2O (in TgN.years-1) estimated by ORCHIDEE in fonction of the fertilizers (in TgN.years-1). In blue is represented the linear regresssion and the grey zone correspond to the confidence interval of the regression.

Figure 4 : Share of the emissions of N2O in ORCHIDEE due to the modification of the N cycle

This figure is obtained by doing the following operations on the annual emisisons : Share of emission = (S1B-S4) / S1B

• with S1B the annual N2O emissions in the S1B simulations
  
• with S4 the annual N2O emissions in the S4 simulations

B - Comparaison of N2O emissions between EDGAR and ORCHIDEE

1 - Maps of emission

The PFT selected in ORCHIDEE to do the comparaison are the following : 10 ; 11 ; 12 ; 13 (only wherethe N_Fertilizants there was striclty positive)

Figure 5 : Global annual emissions of N2O (in TgN.years-1) estimated by ORCHIDEE in fonction of the fertilizers (in TgN.years-1). In blue is represented the linear regresssion and the grey zone correspond to the confidence interval of the regression.

2 - Evolutions of emission between 1860-2015

a) b)

Figure 5: Means emissions estimated of N2O for each region for differents regions by EDGAR and ORCHIDEE for the period 1970-1975 (in Tg N2O-N.year-1). The Standard-Deviation are represented by the variation bar. The regions of temperate Asia, tropical Asia, north America and south America are nammed withe following terms «ATemp», «ATrop», «AN», «AS».

• a) For the period 1970-1975
  
• b) For the period 2007-2012

The bars represents (from left to right) the emissions from anthroposied grasslands estimated by ORCHIDEE, the emissions from crops estimated by ORCHIDEE ORCHIDEE, the emissions from anthoposied grasslands and crops estimated by ORCHIDEE ORCHIDEE and the emissions estimated by EDGAR.

3 - Maps of emission

Figure 6 : Emissions of N2O (en gN.m-2.years-1) to the global scale by EDGAR (a) and by ORCHIDEE (b)

III - NH3 emissions

A = Evolution of the emissions for the 1861-2016 period In ORCHIDEE

1 - Map of the emission

a) b)

Figure 7 : Emissions of NH3(in gNH3-N.m-2.year-1) estimated by ORCHIDEE period for all the PFTs

• a) For the period 1970-1975
• b) For the period 2007-2012

2 - Evolution of the emissions for the 1861-2016 period

Figure 8 : Emissions of NH3 (in Tg.yr-1) estimated by ORCHIDEE for the 1860-2015 period for the whole world

In red is represented the emissions for all the PFTs.

In orange is represented the emissions for the PFTs 12 and 13.

In black is represented the emissions for the PFTs 10 and 11.

In blue is represented the emissions for the PFTs 10, 11, 12 and 13.

In greenis represented the emissions for the PFTs 1 to 9

3 - Effects of the fertilizers on the emissions

Figure 9 : Share of the emissions of NH3 in ORCHIDEE due to the modification of the N cycle

This figure represent : (S1B-S4) / S1B

• with S1B the annual N2O emissions in the S1B simulations
  
• with S4 the annual N2O emissions in the S4 simulations

B - Comparaison of NH3 emissions between ORCHIDEE and EDGAR

1 - Regional emissions

The PFT selected in ORCHIDEE to do the comparaison are the following : 10 ; 11 ; 12 ; 13 (only wherethe N_Fertilizants there was striclty positive)

a) b)

Figure 10 : Means emissions estimated of N2O for each region for differents regions by EDGAR and ORCHIDEE for the period 1970-1975 (in Tg N2O-N.year-1). The Standard-Deviation are represented by the variation bar. The regions of temperate Asia, tropical Asia, north America and south America are nammed withe following terms «ATemp», «ATrop», «AN», «AS».

• For the period 1970-1975
• For the period 2007-2012

The bars represents (from left to right) the emissions from anthroposied grasslands estimated by ORCHIDEE, the emissions from crops estimated by ORCHIDEE ORCHIDEE, the emissions from anthoposied grasslands and crops estimated by ORCHIDEE ORCHIDEE and the emissions estimated by EDGAR.

2 - Evolutions of emissions between 1860-2015

Figure 11 : Emissions of NH3 (in Tg.yr-1) estimated by ORCHIDEE and EDGAR for the 1970-2012 period for the whole world

In cyan is represented the emission of NH3 estimated by EDGAR

The other color represent the same emissions as in the II-A-Figure

3 - Maps of emissions

Emissions of NH3(in gNH3-N.m-2.years-1) estimated
EDGAR
For the 1970-1975 period	For the 2007-2012 period
a)	b)
ORCHIDEE
For the 1970-1975 period	For the 2007-2012 period
a)	b)

IV - Entry and outgoing of N in the system

The entry are as follow : BNF, Fertiliser, Manuer, NHxDepositio, NOxDeposition The outgoing are as follow : N2Emission, N2OEmission, NH3 Emission, NOxEmission, NH4Leaching, NO3Leaching

Figure 12 : Annuals Entries (red) and outgoing (green) of N in the system (from 1945 to 2015)

Figure 13 : Monthly Entries (red) and outgoing (green) of N in the system (from 1945 to 2015)